Effect of caffeinated gum on a battery of soccer-specific tests in trained university-standard male players

The purpose of this study was to determine whether caffeinated gum would improve performance in a battery of soccer-specific tests typically used by teams to assess performance and fitness. In a double-blind, randomised design, ten trained university-standard soccer players (age 19±1 years; body mass 75.5±4.8 kg; stature 1.80 ± 0.10 m) chewed a caffeinated gum (Military Energy Gum, Chicago, IL) that contained 200 mg of caffeine and a placebo gum with the same appearance on two separate occasions separated by 7 days. After a standardised warm up, the gum was chewed for 5 minutes before participants performed a 20 m sprint, a maximal countermovement jump test and the Yo-Yo intermittent recovery test level 1 (Yo-Yo IR1). Performance on 20 m sprint times was not different (caffeine = 3.2±0.3 vs placebo = 3.1±0.3 s; P = 0.567), but the caffeinated gum did allow players to cover a greater distance on the Yo-Yo IR1 (caffeine = 1754±156 vs placebo = 1719±139 m; P = 0.016) and increased maximal countermovement jump height (caffeine = 47.1±3.4 vs placebo = 46.1±3.2 cm; P = 0.008). Chewing caffeine gum for 5 minutes immediately before performing a battery of soccer specific tests enhanced performance by 2.0% on the Yo-Yo IR1 and by 2.2% on the maximal countermovement jump test but had no effect on 20 m sprint times in trained university-standard soccer players.